The only public methadone maintenance program in San Diego County closed in December 1978. As of September 30, 1978 the client population was 561. Two private programs were immediately initiated to continue maintenance at a uniform cost of $100 per month, and approximately one-half of the former County patients enrolled within 30 days. Only some 15 additional former patients have enrolled since that date. The proposed study would conduct an approximate 2-year followup of a random sample of 200 males and 175 females (total population) drawn from the September 30th client population. A comparison sample of 100 males and 100 females would be followed from the combined Orange, Riverside and San Bernardino Counties methadone populations on the same date, controlling for age and ethnic background. The interview is designed to collect retrospective longitudinal data on drug use, criminal behavior, employment and other variables from the time of first narcotic use to the interview. Special emphasis will be placed on assessing behavior subsequent to the clinic closure. The major strength of the proposed study is the unique opportunity to employ a strong comparison sample. The main objectives are: (1) to supplement the findings of the traditional drug treatment evaluation approaches where adequate comparison samples are not feasible; (2) to provide the data necessary for rational decisions concerning the continuation of methadone programs; and (3) to provide an in depth examination of the advantages, disadvantages and limitations of replacing public with private methadone programs.